[argyllcms] Re: Bad gamut mapping from CMYK

  • From: Nikolay Pokhilchenko <nikolay_po@xxxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Mon, 24 Aug 2015 17:59:04 +0300

May be the problem arises only with higher resolution profile, the -qh
parameter?
Coated ceramic media measurements was attached to my previous message. The
profile of same printer with the same inks but textile media with less contrast
(another and much more less bumpy data set) gives no inversion even with less
smoothing factor.
I wonder why the inversion took a place at such high smoothing factor as -r3
I've used.

25 August 2015, 0:23 +10:00 Graeme Gill wrote:

Nikolay Pokhilchenko wrote:
Have tried -S"ISOcoated_v2_eci.icc" without -nP -nS parameters. Seems to be
OK (perceptual):

The data set is a bit bumpy and has some not so well behaved regions, but I
don't see
any problems with black if the source intent used is the same one that the
profile gamut mapping is created for. i.e.:

 colprof -v -qm -sISOcoated_v2_eci.icc RGB_Thermotransfer

 cctiff ISOcoated_v2_eci.icc -ip RGB_Thermotransfer.icm RGB_Thermotransfer.icm
RGBsurfall_cmyk.tif test.tif

looked pretty similar to

 colprof -v -nP -sISOcoated_v2_eci.icc -qm RGB_Thermotransfer

 cctiff -ip ISOcoated_v2_eci.icc -ir RGB_Thermotransfer.icm
RGB_Thermotransfer.icm
RGBsurfall_cmyk.tif test2.tif

in regard to the neutral behavior.

Graeme Gill.




Николай Похильченко

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